Apparatus for cleaning filters



June 7, 1955 A. A. KALINSKE 2,710,099

APPARATqs FOR CLEANING FILTERS F iled Aug. 20, 1949 F j r 5 IN VEN TOR.d'rziorz Z/ZaZarze/rg,

"solids retained, the peresir er t eatres bed or coat halogen APPARATUSFOR CLEANING FILTERS 5 ln'corpi'ate'd, c-hies h, 11L, hamper-stash ofDelaware A plication August '20, 1949, Serial No. 111,505

t CM m 's "(CL marsh liquid is hnered through a f lter -=e1er ehr eonslSllflg a -fil't'er bedof distomseeeuseanhor similar material which Thisinvention relates to filters of'th'e w e whe e n-t e 15 is de osited ona permeable support. More harneuiany the invention relates to means for"and aQniethb dfof cleaning the filter elements of such a filter.Filters hi this general type are sometimes "referred to in "the an asdiatomite filters and will be so designated herein ro'r.s'ifn-'pl'ifica'tion. However, it is 'to be uhde'rstood that Iiibnot wish t'olimitinys'elf thereby to a y parrienla'r fitter efons'tr'uetion orfilter material used the g until,

Below-a predetermined value. hereaf er 'filt or cleaning the filterelem'ents have been suggested, stich as backwashing by a reversal offlow, sometimes aided by streams of Water along the outside of theelements.

More recently it has been suggested in Patent No.

2,423,172 to efiect the retrieval of 'the dirty finer east from theelement and the cleaning of the support by what has been called in theart an air bump 'wasl i. My ihventio'n relates to an improvement in thismethod of cleaning filter elements and to apparatus suitable therefor.

It is an object of this invention to provide aii apparatus andprocessfor cleaning the filter elem ts of a ditear'nite filter which ischeap and simple in 'cbn's't'ru'e- 'tion and reliable in operatibn.

Another ob ect of the invention is to provide a filter of the typedescribed which can be washed by air bti't'has a Which follow.

In sir bump washing assessing to said "Pa-rem "Ne. 2,423,172 air istrapped in the filter bythe liq 1d fliiwin'g from the filter inlet tothe filter outlet and is eo'intiiessed under inlet pressure. One bedy'of air is ce ipressen in the top portion of the filter and another bodyof air is I compressed below the plste which snppojrts the 'filter'ele-I merits, the upper part 6f the elements being'in per'vious. A vent anda 'qliiek aetiii'gair vaiveare previded which permit instantaneousescape of the second or release body of air u'pon' opening of theair'valve. As 35 soon as the release air escapes frern theffilter theofierat- 1 ing air in the top of the filter xfiands anddrives the Waterin the 'upper part of the filter jand the "elements with high veleeityoutwardl through the "elements,

This cleaning-operation has been foiind very eh'eenve.

encountered. Thus,tliiilate'whieh'siifififts the-elements th, Bnt airusin 25 2,710,099 Patented June 7, 1955 'inqsth'e very strong and thejsea'ls between the elements the'plate 'rnustbe perfectly "air tight topermit trap- 6f air t nder the plate ahd prevent its escape. is seastern 'eonstrnction the an tra ped under the "stippe'r'tin'g 'platehas 'sdrnetiiries been lost during thefilteri'ng 'epera'tion and no air-ava'ilabrefor the air-bump It is, therefore, a specific object or minvention to improve the apparatus of Patent No. 2,423,172 and itsoperation to prevent lack of air for the washing operaria and to permita s imp1 ahd cheaper construction.

thaw-roundinglaek df air cah be avoided when the ice air is not siniilytrapped at the beginning of the'filter' run 116 the eafter{stor'ed inthe ter during the entire oh 'withou replenishing it. 1 sugges't to 1itithe i'se fore nder pres ure into the filter n er p'r'e'fer'ably'fdr apart of 'ay he in addition to any air that haspievionsly bee d, or theapparatus may be b be'fate'd without it of air, relying only on the airrune-rinsed into the-ap aratns under pressure. I

The invention will be there cl'early iinde'rstood by reference to thedrawiiig's which form 'a part hereof and wherein shnilar elements aredesignated by the same refere ee c aracters.

Figilie'l'is aneIevatiOn'fiai'tIy in cross-section, of ohe embodimq POfthe invention; I I Fijgu'r gshewsa-iheaifiearienef the apparatus of Fig-P either during ear the run only, This ai Thefiltr bf Figni'e 1eerhprises a casing or housing-:10 era-h cohvenie'nt sli'aii e biltjireferabl y the easing has a enemas beiirrdaiy wen 1 1, a h'o 'fiperbottom 12, and a eeye'r ls. an t conduit 21) equip ed with an inletvalve 21 "discharges ihto the bottom orses of the casing '10.'Awasteoii'tle't 2 2 equipped with a waste valve 23 resashhmtheb'fiitdrh portion of the casing 10. Aplate er part'ition zsexrenashorizontally across the casingand may befastened'tb "the easing by anysuitable means, as by elamp'ing its ""eripheral "edge between the upperedge "of thefvlvallll andthe lower edge of the cover 13-. The 'fila't'e25 'dividest 'hoiisi'rig into a lower inletchamber per'tau et'ehsrnher27.

en ifngon the "size bf plaiit, one or more filter elements 2 8'are'provid'ed iii the inlet chamber 26-. These ems-in fb'e 6f ai'iysuitable tyiae but are shown for herpes-es 6f illiistfation being formedby wire which is helically wound around a cage of foraininous materialin the manner deserilied in the patent t6 Paterson et aL; No.

o 23 1292 7., The'eleiiients are affixed to and supported by th' plate25 and ioreach element as opening 29 is pro- "with which the elementregisters.

fsraesen d is not new and is not yj'" con unction with the new ele- Tvention which berinit improved iae'rtidn 6f the wash.

"of air from the air release space 30 into the outlet chamber 27. Inspite of such complicated and expensive construction it happens that oneor more seals develop a leak and the air under the plate is lost. Toovercome this defect I provide means operable to introduce air into thefilter with the liquid to be filtered, whereby a suflicient quantity ofrelease air is always available for washing of the filter elements.

One suitable means therefor is an aspirator which may be operated by theliquid flowing to the filter or byanother source of liquid underpressure. As shown in Figure 1, the aspirator is operated by the liquidflowing to the A by-pass or auxiliary conduit 40 is branched oil fromthe inlet conduit 20 upstream of the inlet valve 21 and leads back tothe inlet conduit downstream of the inlet valve 21. An aspirator 41 isprovidedin the bypass 40 and when the valve 21 is throttled or closedliquid flowing through the by-pass aspirates air through the air inlet42 of the aspirator into the liquid. The by-pass is also providedwith'valves 45 and 46 upstream and downstream of the aspirator,respectively.

Sometimes it is desirable to provide more than one aspirator and connecteach such aspirator to the filter inlet conduit in similar manner asshown in Figure 1 for the aspirator 41.

. In the embodiment of the invention shown in Figure 1,

the air is introduced only during a part of the filter run andpreferably at the end thereof. The by-pas's valves 45 and 46 remainclosed during a predetermined part of the filter run and thereafter theinlet valve 21 is partly or-wholly closed, and the by-pass valves arepartly or wholly opened, to aspirate a desired quantity of air andintroduce it into the filter with the liquid to be filtered.

By regulating the opening of the valves 45 and 46 and of the inlet valve21, more or less air can be introduced into the filter. When the airladen liquid enters the filter, the air will rise vertically up throughthe liquid in the filter toward the plate 25. Any water that has beentrapped in the air space 30 due to leakage of air, is displaced by theair through the elements into the outlet chamber 27 and thence throughthe outlet 35. Any excess of air over that which can be held andcompressed in the air space 30 will escape with the water through theelements and the outlet. In this manner there is always The aspiratorneed not be operated by the water flowing to the filter but can beoperated by any other suitable asufiicient supply of air in the airrelease space when it source of liquid under pressure. In Figure 2 theaspirator 41a is installed in an auxiliary conduit 47, which may beconnected, to, and receive water under pressure from, for example, acity water pipe, such as the make-up water supply of a swimming pool.The pipe 47 discharges into the inlet conduit 20 downstream of valve 21.Valves 48 and 49 are provided on pipe 47 upstream and downstream of theaspirator 41a. When the valves 48 and 49 are partly or wholly open, theliquid under pressure flowing through pipe 47 aspirates air through airinlet 42a.

The aspirator of Figure 2 may be used as described in connection withFigure 1, during the last part of the filter run. However, in thisembodiment, air can be introduced during the entire filter run, ifdesired, provided suificient pressure is available in pipe 47 todischarge the air laden liquid from pipe 47 into the inlet conduit 20without throttling or closing the inlet valve 21.

The apparatus of Figures 1 and 2 may also be used without trapping air.In this case the apparatus is provided with a vent 50 leading throughthe cover. 13. The

vent 50 is provided with a valve 51. In this method of '1 operation theoutlet valve 36 is closed during filling of the filter, and the airrelease valve 32 and vent valve 51 are held open until the liquid to befiltered has reached their respective levels. Liquid will thus displaceall air in the filter. Thereafter, the valves 32 and 51 are closed andthe outlet valve 36 is opened and the filter run is started. At asuitable time during filtering, preferably toward the end of the filterrun, the by-pass valves 45 and 46 (Figure 1), or valves 48 and 49,respectively (Figure 2) and the inlet valve 21 are set so that apredetermined amount of air is aspirated into the liquid flowing to thefilter. Upon entering the filter the air will rise through the liquid tothe plate and fill air space 30, displacing the liquid under the platethrough the elements. When the air space 30 is filled with-aircompressed under inlet pressure, further air entering the filter will becarried with the liquid into the outlet chamber and rise to its top,displacing liquid from the space 27. By establishing the two bodies ofair in air spaces 30 and 27 just before the end of the run, leakagethrough the seals between the supporting plate 25 and the elements 28will not cause lack of air for washing. Obviously, with the apparatus ofFigure 2, the two bodies of air can be established at any time duringthe filter run and thereafter small quantities of air added continuouslyto make up for any loss of air.

The operation of the filter without trapping of air permitsalso to carryout the washing step with a gas other than air. Sometimes it isundesirable to operate the air- The embodiment of the invention shown inFigure 3 utilizes another means for introducing air into the filter withthe liquid to be filtered. This means is only suitable where the liquidto be filtered is pumped to the filter. In this embodiment of theinvention a centrifugal pump is provided on the inlet conduit 20 whichpumps the liquid to be filtered into the filter. A small air inlet pipe61, provided with a valve 62, is connected with one end to the inletconduit 20 upstream of the pump 60 and with the other to atmosphere,whereby air is sucked into the water flowing to the pump. An air bleedline 65, provided with a valve 66, leads from the upper part of the pump60 and discharges to the inlet conduit 20 downstream of the inlet valve21. The air introduced into the pump 60 will rise to its top, and byproper positioning of the valve 66, a predetermined amount of air can bepassed through the air bleed line into the inlet conduit 26) downstreamof the inlet valve 21 and will be carried into the filter by the waterdischarged by the pump. In this modified apparatus the air may beintroduced during the-entire filter run or it may be only introducedduring the last part of the filter run. In either case there will alwaysbe a suflicient body of release air available for operating the air-bumpwash.

The embodiment of Figure 3 can also be operated without trapping air inthe manner described in connection with Figures land 2.

By connecting the air inlet line 61 to a suitable source of gas ratherthan to atmosphere, any gas can be used as washing fluid also in thisembodiment of the invention.

Obviously, the air under pressure for replenishing the "trapped airbodies in the filter, or for providing the air entirely satisfactory touse atmospheric air and introduce it into and compress it in the filterunder the inlet pressure of the liquid to be filtered.

It will be seen that the invention permits a cheaper construction of thefilter and results in more reliable performance. The invention alsomakes it possible to apply the advantages of the air-bump wash to thefiltering of such liquids which should not be in contact with air duringfiltering.

I claim:

1. In a diatomite filter including a casing having a top, an inlet forthe liquid to be filtered, an outlet for the filtered liquid, an inletconduit discharging into said casing through said inlet, a filterelement interposed between said inlet and said outlet, wall meansforming an air space in open communication with the liquid upstream ofsaid element, said top forming a second air space in open communicationwith liquid downstream of said element, a vent from said first airspace, and a quick acting valve on said vent: the combination with saidinlet conduit of aspirating means for introducing a gas into said inletconduit and discharging it under liquid inlet pressure into said casingduring filtering.

2. The apparatus of claim 1 wherein said aspirating means forintroducing a gas into said inlet conduit comprises an auxiliary conduitdischarging into said inlet conduit, an aspirator connected with saidauxiliary conduit, a valve on said inlet conduit upstream of the pointof discharge of said auxiliary conduit, and valves on said auxiliaryconduit upstream and downstream of said aspirator, the inlet end of saidauxiliary conduit being adapted to be connected to a source of liquidunder pressure.

3. The apparatus of claim 1 wherein said aspirating means forintroducing a gas under pressure comprises a centrifugal pump on saidinlet conduit, a gas inlet into said inlet conduit upstream of saidpump, a bypass leading from said pump and discharging into said inletconduit downstream of said pump, valves connected with said by-pass andsaid gas inlet, and a valve on said inlet conduit intermediate said pumpand the point of discharge of said by-pass. v

4. In a diatomite filter including a casing having a top, an inlet intoa lower portion of said casing, an outlet leading from an upper portionof said casing, an inlet conduit discharging into said casing throughsaid inlet, a valve on said conduit, a filter element interposed betweensaid inlet and said outlet, wall means forming an air space in opencommunication with liquid upstream of said element, said top forming asecond air space in open communication with liquid downstream of saidelement, and means for quickly venting said first mentioned air space:the combination with said, inlet conduit of a by-pass leading from saidinlet conduit upstream of said valve and discharging to said inletf'cfonduit downstream of said valve, an aspirator connected with saidby-pass, and flow regulating means connected with said by-pass.

References Cited in the file of this patent UNITED STATES PATENTS1,452,151 Genter et al. Apr. 17, 1923 1,628,510 Perry May 10, 19271,724,436 Sweetland Aug. 13, 1929 1,922,920 Aherne Aug. 15, 19332,041,048 Chesny May 19, 1936 2,237,882 Lawlor et al. Apr. 8, 19412,239,612 Lawlor Apr. 22, 1941 2,254,597 Berger et al. Sept. 2, 19412,370,772 Bowers Mar. 6, 1945 2,423,172 Booth July 1, 1947 2,468,603 PewApr. 26, 1949 2,570,132 Koupal Oct. 2, 1951

1. IN A DIATOMITE FILTER INCLUDING A CASING HAVING A TOP, AN INLET FORTHE LIQUID TO BE FILTERED, AN OUTLET FOR THE FILTERED LIQUID, AN INLETCONDUIT DISCHARGING INTO SAID CASING THROUGH SAID INLET, A FILTERELEMENT INTERPOSED BETWEEN SAID INLET AND SAID OUTLET, WALL MEANSFORMING AN AIR SPACE IN OPEN COMMUNICATION WITH THE LIQUID UPSTREAM OFSAID ELEMENT, SAID TOP FORMING A SECOND AIR SPACE IN OPEN COMMUNICATIONWITH LIQUID DOWNSTREAM OF SAID ELEMENT, A VENT FROM SAID FIRST AIRSPACE, AND A QUICK ACTING VALVE ON SAID VENT: THE COMBINATION WITH SAIDINLET CONDUIT OF ASPIRATING MEANS FOR INTRODUCING A GAS INTO SAID INLETCONDUIT AND DISCHARGING IT UNDER LIQUID INLET PRESSURE INTO SAID CASINGDURING FILTERING